Short answer:
Green spot algae (GSA) is usually due to a problem with phosphate levels, specifically phosphate levels that are too low (especially as compared to your nitrate levels). The solution is to get more phosphate into your tank, either by dosing with something like monopotassium phosphate, doing more frequent water changes (if your tap water has a decent amount of phosphates in it), or alternatively, keeping your nitrate levels lower by doing more frequent water changes.
Your other problem sounds like Black Brush Algae (BBA). The cause of that is a little harder to pin down but is usually a result of too many nutrients in the water, either from an overloaded tank or from a less-than-ideal water change regime. I know that, of my three tanks, 2 of them I am really good about regular tank maintenance and they are free of the stuff, my 3rd tank I am much lazier about doing pwc's and I have BBA growing in that one. Stocking levels and lighting are pretty similar in all 3, it's really the lack of doing frequent-enough pwc's that is the main difference in the 3rd one. Looking at your list of fish, you certainly don't strike me as being overstocked so I am wondering about your water changes.
As for biological solutions that will help (not solve!) these problems, nerite snails are the only thing I know that will eat GSA. And amano shrimp will eat at least a little BBA. Also, in any tank with algae issues, one thing that can help is having some fast-growing plants that can suck up nutrients before the algae can use them. I realize that nothing grows super fast in 1.2 wpg but some plants would be a lot faster than others--java moss, anacharis, maybe some hornwork, wisteria, etc.
This link might be helpful to you as well.
